Questions tagged [bacteriology]

A subdivision of microbiology dedicated to the study of bacteria.

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130
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1answer
15k views

Do bacteria die of old age?

I know that the cells of mammals at least stop dividing when they are old, and then die a programmed cell death. Then other cells have to replace them. But in a bacterial colony, each cell ...
34
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2answers
14k views

What is the advantage of circular DNA in bacteria?

From what I understand, bacteria have circular DNA. What advantages does it have over linear strands like for eukaryotes? Do there exist bacteria with more than one ring of DNA?
30
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2answers
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If a human takes antibiotics are all bacteria in the body killed?

From my basic understanding, antibiotics kill living things, bacteria for example. Do the antibiotics consumed by a human-being distinguish between what they kill? Or do they just kill every bacteria ...
25
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3answers
5k views

Hot water and bacteria

I know that it is common to say, "use hot water when washing your hands" or when you've got a cut, "wash your hands with warm water," etc. I was wondering, why is this the case? Since bacteria grow in ...
20
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1answer
954 views

Did the Great Oxygenation Event also cause a mass extinction?

It's usually assumed that the Great Oxidation Event around 2.3 billion years ago caused a great extinction of anaerobic life on earth. However, I was reading Nick Lane's book, The Vital Question, and ...
19
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2answers
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How does isopropyl alcohol disinfect less in higher concentration?

Isopropyl alcohol (2-propanol) can be used as disinfectant. For increasing concentration of it in water, the effect as disinfectant increases, and then decreases again. Typical concentrations for ...
18
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4answers
8k views

What causes the development of antibiotic-resistant strains of bacteria?

I understand bacteria have become resistant to antibiotics due to selection pressures, but how do resistant bacteria process antibiotics when exposed to it, compared to non-resistant bacteria. Also, ...
18
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2answers
353 views

Why is there now only one Salmonella species?

Once upon a time, I chanced upon an old microbiology book that detailed the rather colorful world of enterobacteria. Salmonella in particular stood out, as it seemed there were a lot of species: typhi ...
16
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1answer
1k views

Are the bacteria in the stomachs of unborn babies beneficial?

Babies are born with bacteria in their stomachs. I heard on The radio that when a child is given antibiotics for the first time unique bacteria in the stomach are destroyed and cannot be replaced. Is ...
15
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1answer
16k views

How to obtain bacteria samples at home?

As the original question went from hold to closed, I thought I would write up a more appropriate question. How should one go about getting bacterial samples to look at under a microscope at home? ...
15
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1answer
8k views

Why does Penicillin only affect bacterial cell walls

I was quite fascinated by the feature Should Science Pull the Trigger on Antiviral Drugs—That Can Blast the Common Cold? in this month's Wired magazine. They explain that Penicillin is effective at ...
15
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1answer
2k views

What are the requirements for a stable carbon cycle in sealed “bottle gardens”`?

The most famous example of a sealed bottle garden is David Latimer's bottle with a Spiderworth plant, pictured below, which has been sealed for 40 years. My own attempt at a bottle garden is failing ...
14
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2answers
81k views

How do prokaryotes perform cellular respiration without membrane-bound organelles?

In order to survive, prokaryotes such as bacteria need to produce energy from food such as glucose. In eukaryotic cells, respiration is performed by mitochondria, but prokaryotic cells do not have ...
14
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1answer
1k views

How heavy are all foreign microorganisms in and on the human body?

I define "foreign microorganism" as a microorganism which is not produced by the human body (not antibodies or leukocytes) including bacteria, viruses, fungi, biofilm aggregates or small lifeforms ...
13
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3answers
58k views

What is the difference between an antibiotic and an antibacterial?

Concerning medicine, what are the differences between antibiotics and antibacterials?
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3answers
6k views

How long can E. coli stocks be stored at -20°C?

I'm volunteering for a biohacker lab - biocurious in Sunnyvale. The have a pretty good set of equipment - gel boxes, incubators, but they don't have a -80°C freezer yet. I'd like to set up some ...
12
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2answers
2k views

How is the concept of species defined in asexual organisms?

In asexual organisms such as bacteria, archea and some fungi, as well as in some plants where asexual reproduction is the only reproductive strategy, how can we be unambiguous in defining if an ...
12
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2answers
249 views

Is there an equivalent to “Fields Virology” for Bacteria?

I've gotten a staggering amount of use out of my copy of Fields Virology as a general reference for "getting me up to speed" on whatever pathogen I'm currently looking at. I don't know of a similar ...
12
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3answers
1k views

How are antibiotic resistant bacterial infections treated?

For example, how are infections of antibiotic resistant strains of MRSA, Streptococcus, or Gonorrhea treated?
12
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1answer
643 views

What bacteria do unborn babies contain?

This Scientific American article states that "[human] infestation [by bacteria] begins at birth". This would suggest that unborn babies are free from any bacteria. However, if the mother catches a ...
11
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2answers
10k views

What is the advantage of using starter cultures for growing bacteria?

Many DNA isolation and protein expression protocols contain instructions to use a starter culture of E. coli that is then used to inoculate the main culture. What are the advantages of using starter ...
11
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2answers
5k views

What kinds of bacteria live in water bottles?

I've always heard not to re-use disposable plastic water bottles. According to this Huffington Post article, the reason is because: everyday wear and tear from repeated washings and reuse can ...
11
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1answer
546 views

What are the functions of magnetic bacteria?

I'm trying to understand why are bacteria "equipped" with magnetosomes ("intracellular organelles in magnetotactic bacteria that allow them to sense and align themselves along a magnetic field") and ...
11
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1answer
1k views

Why don't vaccines cause bacterial resistance?

Since bacteria can evolve to overcome antibiotic use, why wouldn't they be able to evolve to overcome antibody or cell-mediated immunity? (One possible explanation: antibiotics have only one target ...
11
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2answers
12k views

Why would taking antibiotics increase stamina and energy?

I often hear that people who are taking antibiotics experience wild fluctuations between feeling full of energy and completely alert but soon after feeling impossibly fatigued and sick. Does this ...
11
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2answers
1k views

Do antibiotics attenuate immune response on subsequent exposure to same bacteria?

A healthy immune response to a bacterial infection includes "memory" to permit the body to thwart subsequent exposure to same bacteria. What are the dynamics of using antibiotics on initial exposure ...
11
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2answers
788 views

Can bacteria release free DNA into their environment?

Natural transformation AKA natural competence involves the uptake of DNA into a competent bacterium (for horizontal gene transfer or as a food source). My question is about where this extracellular ...
11
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1answer
507 views

Are these Gram stain substitutions acceptable?

In the context of a Gram stain on a blood smear: Are the following acceptable substitutions and/or what differences could arise by substituting them? Using methylene blue instead of crystal violet ...
10
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3answers
19k views

Why do Type II Restriction Endonucleases cleave at palindromic sequences?

Type II Restriction enzymes usually cut only at palindromic sequences. Is there any specific reason for that? Is there any advantage for bacteria if they cleave phage DNA at this type of sequence?
10
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1answer
510 views

What advantage would the initial 'donor' in horizontal gene transfer by conjugation have received?

I am struggling to think why horizontal gene transfer between bacteria would have persisted during the course of evolution as surely it puts the 'donor' at a disadvantage? For example, consider a ...
10
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1answer
5k views

How long can Cholera bacteria survive in a dead host?

How long can cholera bacterium survive inside a dead host? Can they remain dormant in such conditions? BACKGROUND On a hill not far from where I live, there was a hospital operating since 16th until ...
10
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1answer
907 views

What bacteria shed harvestable energy from root zone organic matter?

I recently heard of a successful effort that harvests energy from soil at plants' bases due to apparently bacterial breakdown of wastes from the plants: Via photosynthesis a plant produces organic ...
9
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4answers
26k views

Does a microwave oven disinfect food?

Imagine I am preparing food -- just about to put it into a microwave oven -- and some of it falls on the floor. Assuming it got some bacteria or other organisms (viruses?) on it, will the microwave ...
9
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2answers
498 views

Where do the bacteria within the vagina originate from?

I understand that it's feasible the bacteria within the gastrointestinal tract originate from the food we eat and air we breath, but where does this population of microbes originate from?
9
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2answers
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Are there grass or fiber eating birds?

My understanding, that may be wrong, is that cellulose/fibre has little nutritional value to many animals because it's hard to break down thus making consumption inefficient. However, Ruminating ...
9
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2answers
3k views

Does rainwater contain many fewer micro-organisms than river water?

From watching many documentaries on micro-organisms, I can tell water typically contains quite a lot of them. But what about rainwater? (before it hits the ground). I know nothing about any micro-...
9
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1answer
253 views

Can a bacteriophage be used to treat bacterial diseases?

Some bacteriophages reproduce using the lytic cycle which ends with the destruction of the host bacterial cell. I was wondering if theoretically this could be used theraputically to treat bacterial ...
9
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2answers
196 views

Is taking a shower unnecessary if good bacteria surround our skin?

David Whitlock, a scientist, has not taken a shower for 12 years. Instead, he sprays a bacterial mist containing live bacteria to remove odor and maintain the number of good bacteria. It is because ...
9
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1answer
8k views

Why are pili more common in Gram negative bacteria than in Gram positive?

Although pili have been observed in some species of Gram positive bacteria, the preliminary research that I have done indicates that pili are significantly more common in Gram negative bacteria. Is ...
9
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2answers
1k views

Which bacteria have the highest mutation rate?

From my reading on M. tuberculosis, I know that this organism has a pretty high mutation rate due to uncorrected sloppy replication, which leads to a high rate of development of spontaneous resistance ...
8
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2answers
10k views

Why pick just a single bacterial transformed colony

So after bacteria have been transformed to perhaps grow up a plasmid of interest, why pick only a single bacterial colony from a selective plate for further expansion? I understand that this is to ...
8
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1answer
1k views

Are bacteria necessary for an individual's life, or, how long could a person live without bacteria? [closed]

Bacteria are essential to life in that they are responsible for breakdown of organic substances, etc. but are bacteria necessary for an individual's life? In other words, how long would a human ...
8
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1answer
22k views

Rust on kettle dangerous to consume?

I recently traveled to Japan, where I picked up a cast-iron kettle known as a tetsubin. When I opened it up, I found that the inside was heavily rusted. Rust is a result of various combinations of $\...
8
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3answers
706 views

What would cause E. coli to change from filamentous growth to normal growth?

In my lab we've observed a phenomenon in which a culture of E. coli is found to shift from normal rod growth to filamentous growth and then back to normal rod growth again several times over the ...
8
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2answers
3k views

How can E. coli proliferate so rapidly?

The E. coli has a genome with approximately 5×106 bp. The main DNA polymerase involved in its chromosome duplication (DNA pol III , the one with highest processivity) can polymerize ~103 nucleotides ...
8
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1answer
4k views

Why do bacteria produce H₂O₂?

I recently read up that people with NADPH oxidase deficiency (Chronic granulomatous disease CGD) have a tendency to be infected by Catalase positive organisms. NADPH oxidase helps produce the $H_2O_2$ ...
8
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1answer
505 views

How often does bacterial transformation happen?

I have been reading: M. Dröge, A. Pühler, W. Selbitschka, "Horizontal gene transfer among bacteria in terrestrial and aquatic habitats as assessed by microcosm and field studies", Biol. Fertil. ...
8
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2answers
597 views

How and when did sex evolve?

As I know evolution comes bit by bit mutation by mutation How sex evolved which requires a major change in at least two individuals one to become male and one to become female ? When that happened ...
8
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1answer
701 views

Aren't antibiotic resistant probiotics dangerous?

Multidrug resistant probiotics are often recommended by doctors in various cases. But since bacteriae can easily exchange genes by conjugation or other means they could promote the drug resistance of ...
8
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1answer
163 views

Is this a bacterial colony?

On the physics StackExchange site people are trying to figure how and why these branching structures formed. The two questions can be found here and here. The latter had no cooling fans and was ...